The present invention relates to a method of producing a concrete lined tunnel or other concrete lined excavation.
In such methods as known in the art, a rough tunnel is first excavated and the space between the inner surface of the rough tunnel and the desired inner surface of the finished tunnel is filled with concrete. Due to the irregular inner surface of the rough tunnel, on the one hand, and the expected settlement of the inner surface due to the rock pressure acting thereon, on the other hand, the concrete lining has to be formed relatively heavy which requires a large amount of concrete. In order to at least partially obviate this disadvantage, it has already been suggested to wait with the application of the concrete lining until the rough tunnel has settled. The dimension of the settlement of the rough tunnel may in the uppermost portion of the latter be up to 70 centimeters and the time of such settlement may be 3 to 4 years. This last-mentioned method has, therefore, the disadvantage that a considerable time span is necessary between the excavation of the rough tunnel and finishing the tunnel by applying a concrete layer to the inner surface thereof.